# CVE-2026-10532: QOS.CH Sarl logback-core restricted deserialization in HardenedObjectInputStream

Source: https://junglewise.ai/threats/cve-2026-10532-qos-ch-sarl-logback-core-restricted-deserialization-in  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-06-01. Updated: 2026-07-08  
License: CC BY 4.0 with a link back

CVE-2026-10532 · Severity: medium · CVSS 4 · Published 2026-06-01

Logback is a popular logging framework used by Java applications to record system events. A vulnerability in its socket-based logging servers could allow an attacker to bypass security restrictions by sending specially crafted data. While the risk of full system takeover is considered low, it allows for unauthorized object creation within the application's memory.

Technologies: [ch.qos.logback:logback-core (Maven)](https://junglewise.ai/threats/technologies/ch-qos-logback-logback-core), [QOS.CH Sarl Logback-Core](https://junglewise.ai/threats/technologies/logback-core). Vendors: [Maven](https://junglewise.ai/threats/vendors/maven), [QOS.CH Sarl](https://junglewise.ai/threats/vendors/qos-ch-sarl).

## Quick answers

**Is CVE-2026-10532 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-10532 being exploited in the wild.

**How severe is CVE-2026-10532?** Medium severity, with a CVSS score of 4, published 1 June 2026.

**Which products and versions are affected?** ch.qos.logback:logback-core (Maven) < 1.5.35, ECOSYSTEM:introduced=0,fixed=1.5.34; QOS.CH Sarl Logback-Core <= 1.5.33, through 1.5.33 inclusive.

**Is there a fix for CVE-2026-10532?** Yes. ch.qos.logback:logback-core (Maven): upgrade to 1.5.34 or later. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

**How is CVE-2026-10532 attacked?** It is attacked over the network, in a software library.

**Am I affected by CVE-2026-10532?** Check whether you run ch.qos.logback:logback-core (Maven) or QOS.CH Sarl Logback-Core at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

## How to fix

- ch.qos.logback:logback-core (Maven): upgrade to 1.5.34 or later

  ```sh
  # set ch.qos.logback:logback-core to 1.5.34 in your pom.xml or build.gradle
  ```


## Technical details

A deserialization of untrusted data vulnerability exists in the HardenedObjectInputStream module of logback-core. An attacker who can influence serialized data sent to SimpleSocketServer or SimpleSSLSocketServer can bypass intended security restrictions to instantiate Proxy objects. While the HardenedObjectInputStream heavily restricts deserialization, this bypass allows for limited object injection. No practical remote code execution (RCE) or significant privilege escalation gadgets have been identified at this time. The issue is addressed in version 1.5.34 by explicitly throwing an InvalidClassException when attempting to deserialize Proxy classes.

## Affected products

- QOS.CH Sarl logback-core <= 1.5.33

## Identifiers

- CVE-2026-10532
- GHSA-jhq6-gfmj-v8fx

## Timeline

- 2026-06-01: disclosed
- 2026-06-01: advisory
- 2026-06-01: patched: Fixed in version 1.5.34

## References

- [https://logback.qos.ch/news.html](https://logback.qos.ch/news.html)
- [https://github.com/qos-ch/logback/releases/tag/v_1.5.34](https://github.com/qos-ch/logback/releases/tag/v_1.5.34)

## Related threats

- [QOS.CH logback-core deserialization bypass in HardenedObjectInputStream](https://junglewise.ai/threats/cve-2026-9828-qos-ch-logback-core-deserialization-bypass-in)
- [Logback allows an attacker to instantiate classes already present on the class path](https://junglewise.ai/threats/cve-2026-1225-logback-allows-an-attacker-to-instantiate-classes-already-present)
- [QOS.CH Logback-core code execution in conditional configuration processing](https://junglewise.ai/threats/cve-2025-11226-qos-ch-logback-core-code-execution-in-conditional-configuration)
- [QOS.CH logback-core Expression Language Injection vulnerability](https://junglewise.ai/threats/cve-2024-12798-qos-ch-logback-core-expression-language-injection-vulnerability)
- [QOS.CH logback-core Server-Side Request Forgery vulnerability](https://junglewise.ai/threats/cve-2024-12801-qos-ch-logback-core-server-side-request-forgery-vulnerability)